Method of and apparatus for making ink, etc.



A. L. MILLER June 24, r19.30. v

. METHOD oNl AND APPARATUS FOR MAKING INK, ETC

Filed Feb. 28, 1927 6 Sheets-Sheet 1y R. mw n N. N EV R V w N T AWY B .WN fw v Niv/ bw l s vw ON @Q ..9

June,v 24, 1930.

A. L. MILLER METHOD 0F ANDl APPARATUS FOR MAKING INK, ETC

Filed Feb. 28. 1927 6 Sheets-Sheet 2 June' 24, 1930. A. j.. MII- LER METHOD. or' AND APPARATUS FOR MAKING INK,` a`rc INg'ENToR:

ik@ A TTORNEY .June 24, 1930.-

A. MILLER METHOD 0F AND APPARATUSKFOR MAKING INK, ETC

Fi1ed Feb. 2S, 1927 esmas-Sheet 4' fili' ai f s.

INVENoR:

June 24, 1930. A. l.. MILLER I METHOD OF AND APPARATUS FOR MAKING INK, ETC

Filed Feb. 28

1927 6 SheeitS-Sheekl 5 ATTORNEY June 24, 1930. A, "L MILLER r1,765,991

METHOD OF AND APPARATUS FOR MAKING INK, ETC

Filed Feb. 2B, 1927 6 Sheets-Sheet 6 [JINI/mm2: BY @a 2;'

@ATTORNEY Patented y' .Y f i l j.'

UNITED S'TAras-)PATE-Nr oFF'lcE mos L. MILLER, onrnILADELr-HIA, rn'nnsvmm, .assioma 'ro rma: ULT a wmone co.,or.cmcmnar1, omo, a Vcoiuomlrron'or omo nnrnon or aiiaafa-Arus.ron nume' mx, nrc.

-appmmbnfaied-rebfuary as, iosa semi no. inns..

This invention relates to the production of inks, especially carboniferous printing inksA and also, as an intermediate product, finely 'divided carbon or' soot, this lapplication being ya continuation in part ofmy copending applications, Ser. N o. 600,248, filed Nov. 11, 1922, for process and apparatus for producing carbon black; Ser. N o. 26,913', led Aug. 30, 1925, for method and appara? 1o tus for dealing with particles in gaseous suspension; Ser.vNo. 26,914, filed April 30,

1925, for manufacture of lamp black and ink and Ser. No. 719,506, yiled June 12, 1924, for

manufacture of lamp black as to common subject matter therein described.

The particular ob'ects of the invention are the eiiicient, economical and expeditious .production of carboniferous inks-of high quality and also theefficient production from hydrocarbonv oils and gases, of a finely divided carbon product or sootl suitable for theV manufacture of such inksl and for various other purposes requiringv a high grade carbon product in a nely divided condition and which soot is of good tnctorial strength, is in a highly ilocculent condition and of a high degree of purity.

Further objects of the invention `are the provision of an efficient apparatus suitable for the production of such inks and soot, which apparatus is highly efficient, easily controlled and relatively inexpensive to construct.

In the accompanying drawings, in which I have illustrated a preferred form of apparatus suitable for carrying out one form of my invention. f v v Figure 1 is a diagrammatic plan view of such apparatus;

through the furnace unit;

Figs. 3 and 4 are transverse vertical sections taken respectively on the lines 3-3 and 4--4 of Fig. 2;

Fig. 5 is a fragmentary horizontal section showing essentially the burner element il-A lustrated in Figs. 2 and which is a type suitable for burning hydrocarbon oils;

Fig. 6 is a fragmentary vertical section 59' showing a type of burner whichit is dev sleeve 11, although obviously any suitable 10ul Fig. 2 is a vertical longitudinal sectionl lsirable to employ when burning natural gas or other'hydrocarbon gas; v

' Fi 7 is a vertical longitudinal section of the collecting unit;

Fi' 8 is a transverse the line 8-8 of Fig. 6; .Y Fig. 9 is a verticalsection of an alternate form of collecting'unit, isolated;

Fig. 10 is a horizontal section on the line 10-10 of Fig. 9; and

Fi 11 is a fragmentary plan view show-l ingt e collecting unit hooked up in the system. i Y.

'Referrin to the drawings and the construction s own therein, the reference numeral 1 designates the shell proper`ofthe furnace and 2 a water jacket which is adapted to cool the upperunprotected portions of the shell of such furnace whereas a refractory linin composed of suitable rebricks 3 serves or protecting the hearth as well as the shell at the front and d the furnace, as indicated, from the intense heat of `the products of combustion within the furnace. As shown, .the top of 'the furnace, as

well as the upperfrontv wall of the shell, are

protected solely by the water jacket.

At the frontvof the furnace I provide a cylindrical extension 4, in which is posiv tioned a pipe section 5, lalso of suitable refractory material, the same being so dis-- posed as to provide vertical lair passages b and c, and an annular air passage d, all in vertical section onl communication with a central or main duct e, as indicated. 1

Manholes 6, and 6 afford accessto the burner of the furnace for the introduction of oil soaked waste or other combustibles used for igniting purposes, or forthe cleaning of the burner or other purposes. The said extension 4 has an apertured rear wall 7 to which is secured a supplemental cylindrical extension 8 that encloses the burner nozzle and the casing 8` is provided at its lower end with an air port. 9.

In the oil burner lconstruction shown in detail in Figs. 2 and', an oil feed pipe 10, which terminates in a nozzle l0', is centrally disposed within the tubular casing or surrounds the refractor burner ofwhat might be termed the Bunsen type, adapted to admit regulatable quantities of air and hydrocarbon fuel, as petroleum oil v:for example, are suitable for this purpose. A low pressure pre-heated. air supply pipe 12 serves to admit air laterally into the annular chamber c, which latter section 5, said pip'e- 12 being connected y aT 12', section 13 and valve 14 with a T 15 that serves to connect the valve 14 and another T 16 with the preheated air inlet 17. A portion of the reheated air is supplied to the bottom of the burner casing 8 from the inlet 17, throu h the T 18 section 19, T 20, sections 21 an which serve to conduct the preheated air to the port 9.

A steam line 23, provided with a @clp-23', serves to admit steam when the same is desired, through a 'l' 24 into the sleeve lland the pipe 25, which also'` is connected to the l"l" 24 and provided with a control cock 26,

serve to admit high pressure air to said sleeve 11. A cock 27 admits of the regulated supply of fuel oil or other suitable hydrocarbon oil roman oil suppl pipe 28, adapted toy be connected to a suita le source of oil supply, to the feed pipe 10 and nozzle 10 At the rear end of the furnace is a preheater of the usual type wherein the entering atmospheric air passes through a pipe 29 and is caused to circulate around a series of tubes 30, the internal surfaces of which are in direct ,contact with and are heated by the hot furnace gases. A suitable blower 31 serves to draw atmospheric air into thel preheater and force the same into the preheated air supply pipe 17.

From the preheater the carboniferous furnace gases are conducted through the outlet pi e 32 to branch cooling pipes 33 and 33', w ich in turn communicate with the front end of a soot collector unit.' This unit in the construction shown in Figs. 7 and 8, comprises a cylinder 34 provlded with a central longitudinal shaft 35 on which are mounted a plurality of flat discs 36, that are spaced from each other approximately 1 to 1%. Said discs each have a circular series of apertures 37 or 37', the series of apertures 1n one Vdisc being in staggered relation to the series of the` next adjacent disc o discs whereby a tortuous passage of the productsof combustion through the coltector occurs and a more effective collection or absorption by the oil vehicle with which the discs are drenched is insured.

, Preferably these apertures are of considerable cros-sectional area, for example, for a series of 32 discs each ofabout 30 in event, the apertures should be of suiiicient 21 and the interposed T 22 all of' size to prevent an injurious back draught or backing up of the gaseous products into the furnace with Ia consequent retardation of the velocity of the gases issuing from the furnace, as otherwise the proper conditions of operation for the production of soot of the desired quality in -the furnace cannot be maintained.

The shaft 35, as shown is adapted to be rotated by means of suitable gearin in the well known manner and preferably te same is operated at approximately 30 revolutions per minute in a collector where' the discs are approximately 30 in diameter and the ow o the gases of combustion v,entering the collector thrpugh thefinlet, such as the pipe 38 of 10'?, diameter is approximately 3,000 ft.,

. per minute. From the collector the gases are caused to pass through an outlet 39 and thence to a suitable stack`40, which latter may, if desired, be provided with suitable high tension dust precipitators or other suitable dust collectors to insure the collection of further quantities of soot Jfrom the exit gases.

Durin the rotation of the discs in the collector, t e same, as shown, are alternately submerged in the vehicle of a printing ink, lsuch vehicle, for example, consistin of heavy petroleum oil of a viscosity 600 (Sayboldt) at- F., althou h the same maj/.comprise any other ink ve icle capable of producing ink vof the desired quality by the absorption thereinto or admixture theref with of the carbon black or soot.

The ink vehicle in the collector is maintained in constant circulation, the same entering through the inlet pipe 38 and being drawn through the outlet 39 by means of a rotary pump 41` which discharges into the circular circulation tank 42. The circulation tank, when operating in an apparatus wherein approximately 50 gal. of fuel are being consumed per hour and wherein the collector is approximately 30 in diameter-and 8 ft. long, is preferably of about 10,000 gal. capacity and is originali charged with about 8,000 gals. of oil to a low space forthe increase in bulk of the material as the carbon black or soot is absorbed thereinto. Such tank is unjacketed so as to permit of the same being automatworking` temperature by the atmosphericv air surrounding the same. Suitable heating coils 43 in the bottom of the tank 42 for initially heating the ink`vehicle to the necessary working temperature of about 100 F. or at least to a sufiicient temperature to prevent the vehicle employed from becoming so viscous that a film will temporarily form across or substantially across the opening inthe collector plates as they emerge from the oil vehicle and thereby seriously aiect ically cooled and maintained at the proper fle 1 plate y is '-example, it is necessari the normalliiow and pressure of the gases in the collector.

' When it is desired to yutilize as ay fuela.

entering through the annular duct d. The

vertical ducts band the central bore e correspond with the similar duct b and bore.

e of the oil burner previously described. f

The alternate form of collector unit shown in` Figs 9,` 10 and 11 v comprises a centrifugal spray scrubber associated with an electric precipitator. Refer-rin alternate construction shown in Figs 9, 10 and 11, the reference numeral 45 designates the curb or' bowl offa jcentrifugal spray.

scrubber which is 'sub-divided into two compartments 46 and 47 by a cone "shaped wall 48. A'revolving disc 49, tothe underside of which are attached a series of fan blades 49', is mounted lon the top of a vertical spindle 50 which is carried in suitable bearing and adapted to be driven at high speeds, for example- 1200 R. P. M byv a verticalmotor 51. The rotation of said disc 49 uniformly spreads the ink vehicle .introduced from the pipe 38 and breaks it up into small 'drops each of which leaves the disc with a planetary motion and these in turn breakup into small drops as the surface tension is reduced. This forms a liquid curtain of uniform density which due to the rotation of the component particles or dro s thereof, oers little or no resistance to t e passage of as directed through the annular passage 52 y the action of the fan blades 49.- Said blades alsov serve to draw the gas into the compartment 47 through the bottom inlets thereof from the branch pipes 33, 33 and to impart the'necessary velocity lto the soot (laden,v gas to cause thev same to impinge .as *a .blast against the liquid cur tain thrown off: thev perimeter ofthe disc 49. l 'As a consequence .of the foregoing mixing action, the lcarbon-,laden gases will .become intimately mixed with the` ink vehicleand; ythe greater part, about. of the carbon wiil become incorporatedp therewith.

From the chamber-orwell 47, the .carboniferious ink vehicle vvisl .discharged through the outlet* pipe-` 39', bei-ng withdrawn by the pump 41, in-the same manner as when employing the previously described to the f type of collector,\and circulated through the tank 42 prior. to beingreturned `by means of the pump 44 to the Abowlyof the collector.

The electrical precipita-tor -which ispreferably associated directly with thel spray scrubber to form the-collecting unit, renders it possible to recover the soot particles not precipitated or absorbed bythe scrubber, the

same approximating about 5% of the total soot vsolids produced .in the.l furnace.

The electrical precipitator is supported by l the bowl 45` and comprises thetube or cylinder 55 which is flanged at the bottom and top to admit of the same being bolted to a corresponding iange on the bowl 45 and also to. receive a centrallyapertured cover 56 respectively. An annular receptacle 57, having vertical walls 58, 58, is supported on the cover 56and the samel servesto'sullilport the 1 i high tension insulators 59, 59 lwhic in'turn support the cross-head 60 of copper or like conductive metal. A` rod 61, depending from the cross-head, carries la bell 62 and a grid 63 from which latter in turn are suspended weighted cathode wires 64 that project vbetween anode plates 65 carried by and electrically connected'with the tube 55 by means of a second grid 66.`

The receptacle 57 contains abody of trans,-

former oil or the like ywhich is circulated therethrough from an auxiliary tank 67 by means of a pump 63, supply pipe 69 and outlet pipe 70. The latter plpe 1s located at a A.

level above the lower edge of the bell 62 so as to effect a liquid seal around the outlet conduit 71 which 1s in registry with the central aperture of the cover 56. As shown, the conductor 60 is connected to'one lead a: of a high tension grounded circuit and the tube 55 is grounded as indicated at y. The waste gases freedl of their l-soot escape through the outlet 7,2.

When employing an lelectrical ercipitator, the tube of which is approximately 5 ft. in diameter, for the purpose of recipitating from the waste gases passing t rou h the spray scrubber, the soot particles in t e form of sticky, flocculated masses of such specific gravity that they will automatically flake off the collector when the layer of soot susy thereon extends about 1' in thickness, I have found that a non-arcin or corona. dis-I j charge which is maintained y a current of 45,000 to 50,000'volts`- and about 2 amperes is su'iiicient to accomplish these` results when employinganodeplates of 'about- 32 in width, '11 thickness-and 6 ft. long and the cathode wires are spaced therefrom about 4"-,

The sootparticles inthe waste ga'sfrom the scrubber containing as they do aboutv 20% of oil vehicle and some 10% of water can be 4recovered from vthe waste gases to a remarkable extent, and as these sticky oilladen soot particles detach themselves from the plate, they are notv entrained, the'. veloc- :sof

Y:sa

4 ity employed is say 250 per minute by the current through the gas outlet 72 of the precipitator, but owing to their high specific gravit ,they fall in the form of .coarse flakes into t e circulating 011 contained in lthe chamber 46 and because of the fact that they already have oil incorporated therewith they are readily miscible `with and become intimately' incorporated in such oil vehicle in such chamber. Otherwise, if the soot particles were dry and did not contain appreciable amounts of oil, the problem of preventing the same escaping from the outlet 72 and removing the saine from the plates would be a most serious one. A

The aforesaid waste ink ingredients comrising oil-laden soot which are recovered m the mist of oil-soot-laden gases passing into the recipitator from the spray scrubber would be valueless for use as dry lamp black because of the sticky nature thereof due to the presence of oil therein and also due to the extremely small percentage of the same in the gases leavin the scru bers, some 5%, the monetary va ue thereof for any pur ose is almost negligible. Nevertheless, t is oil-laden soot, because of theI fact it is in a peculiarly suitable condition` for incorporation with the ink vehicle, is a useful ingredient for the ink produced in the manner herein described, but quite aside from its usefulness for this purpose, the elimination of this soot from the waste gases passing through the outlet 72 is of the utmost importance from an' operation standpoint, 'as ink works would ordinarily be installed in relatively congested districts where smoke ordinances usually are in force and consequently it is possible to accomplish the effective' removal of the soot from the 'stack gases.

When it is considered that the concentration of the soot in the gases delivered into the spray scrubber is approximately fifteen times that of the gases obtained from the burning of oil in so-called open air tray burners, diliculties of collecting, as well as the importance of such collector can be more readily appreciated.

The ratio of the air to the hydrocarbon fuel employed is preferably maintained in order to secure the best results approximately constant, as a mere dilierence of 10% in the amount of air supplied above or below critical or optimum ratio will deleteriously aiect the quality of the black obtained. Accordingly, when operating with hydrocarbon oil the proportion of air (preferably preheated) to the oil should be about 7 to 1 by weight, but in no'case less than 5 to 1, nor more than 9 to 1. In order to maintain the ratio at or near such optimum, it is not only necessary to directly regulate the rate of air and oil feed, but to indirectlycontrol the rate of air feed through the maintenance of incassi certain optimum conditions in the furnace, in the cooling pi es, in the collector and also when the lwet co ection is resorted to,'in the circulation tank. These optimum conditions require that the velocity of the hot gases in the entrance end of the branch cooling pipes should be maintained at not less than 500 ft. and not above 6,000 ft. er minute in order to insure the requisite co ection of the finely divided solid carbon particles by impact of the same against the collection plates and preferably a velocity of 3,000 ft. per minute is employed. f At these high velocities the relative diierence between the densit or specific gravity of the carbon partic es to the gaseous medium in which they are suspended will tend to cause the carbon particles to continue in a rectilineal course and impinge against the interposed surfaces of the collectorplates instead; of being deiiected from their path and following the 'nsv deflected gases through the apertures in such collector plates as would ordinarily be the case were the gases to pass through at a low velocity such as, would be the case in a sedimentation collecting chamber. Furthermore, the collector plates, especially in the front end of the collector should be spaced sulciently farapart to prevent the impacted masses of carbon collected on the plates from choking the circulation of the gases through the collector. Again, the temperature of the furnace should not exceed about 3,000 F. and should be in excess of 2,000 F. The cooling pipes should be of considerable length, for example in an apparatus of the size'described herein 8 pipes of a length of 50 ft. each are found desirable in order that the gases will be air cooled in their passage to the collector, since if the gases were cooled by contact with water-jacketed, chilled surfaces, the carbon particles would tend ,to accumulate in thick layers on the inside of the pipes until the layers were so thick as to serve as effective insulation, whereupon not only would the circulation of the system be affected, but the cooling of the gases in their passage to the collector would be prevented.

In the collector it isgimportant that not only the temperature should be maintained considerably above thecondensation point of water, but below the point at which the ink vehicle, when the same is employed in the collector, will substantially volatilize. If dry collection is resorted to, a temperature below that at which the issuing stack gases will spontaneously ignite upon contact with the atmosphere is desirable, not only because of' iire risk, but also because of the-diliiculty of preventing the buckling of the iron orsteel plates in the collector if the same are sub- Jected to the action of'such hot gases. Accordingl the temperature of the gases entering t e collector is maintained between 250 F. and 1100 F.,when operating with an ink vehicle in the collector, and prefer- .ably at about 600 F. when an ink vehicle, of

Aing b virtueof t initial boiling point of 350 F. to 400 F. is employed so las not ,to heat the "same substantially about 270 F. to 300 F. ,If the' temperature of the gases inthe dry collector is toohot,"there'willalso be a substantial decrease in the amount of black collected by impact as the tendency for the particles to cling to both the bare metal and to eachv other is considerably affected by excessive tem `ratures. c. Y u

T e ink'v'ehicle while initially heated, as herein stated,'is

Even'the speed of rotation of the plates of the collector 'is-an important factor in the production of soot of the desired quality, as 1f the rate ofrotation is too slow, the ink vehicle, vwhen emplcyin'g set collection, will be incapable of e ectively lcleansing the plates fromtheirdeposits and hence there will be anaccumulation of]A carbon on the plates and a serious `choking of the circulation through the system.

When supplying fuel atthe rate of about 50 gals. per our under the above described conditions of operation and while maintaining the relation between the burner 10 and its sleeve so that in nopartof vthe furnace y a blue iame is visible, it will be'possibleto maintain the temperature in the furnace at about 2600 F. and an outer envelope ofl v the gaseous products of combustion of the increasing cross-sectional area. The longer the soot lis heated, the more it oil and 'air will completely surround a central cone comprising the decomposition products of the oil, includin a large volume of particles 4of soot,'wh1chcone, commencing at the burner-,will be of gradually becomes roasted and approaches graphite. Therefore, in order to minimize the time of contact of the .soot particles with the. lot

` gases in the furnace, it is essential that the velocity of the gases and the rateV of fe'e'd f eo of the oil be maintained within the above 'specified limits. If a large quantity of oil,

as4 compared with the air, is fed 1nto the furnace, the airwill continue to consume the same for a vrelatively great distance profducingl an excessively long flame, whereas vif a sma a relative short hollow cone of -combustion results, 0r in-other words, the

vas

smaller the quantity of'air, the lon er the flame and vice versa. Preferab y," the amount of oilemployed vis approximately brick arches'l whic prevented from overheate relatively large volume -rent of `air is caused to closed none of such air will uantity of oil relative to the air is 'f employe complete combustion with the same quantity of air.

In the furnace, the water-jacketed metal top shell serves to eliminate the diiculties that would be explerienced with refractory rapidly .deteriorate unf 5 doublev that which would be required for l -der the conditions of operation experienced v i in such a furnace due to the chilling action and consequent chi ping or disintegration of such brlcks by t e impingement thereon .of small masses or drops of unvolatizedoil or tar particles. The said-watr-jacket prevents the excessive heatin of the inner surface of the top -shell of t e furnace owing to the insulating film of carbon which forms on water cooled metal, and consequently substantially no deleterious action such as results from the masses or drops of unvolatilized oil or tar particles from the burner impir'gng against a brick arch can occur`.

e refractory section 5 also has, an im- .portant function in that it protects the flame directly as it issues from the burner,

and until the same hasbeen substantially established, from excessive lateral exposure due to llar e volumes of air entering through the conduitv 12. As a result, a constant curiass through the passages c and strike the lme at some dis-l tance from the burner, thus not only affect- `ing the substantial shortening of the incandescent outer envelop of the flame, Ibut increasing the diameter of the inner uncombusted-carbon-laden hydrocarbon zone within the furnace whereby the quantity of hydrocarbonwhich will be destructively decomposed is greatly increased without the combustionlthereof, sincel by the inter osition of this cylinder or section the relatlvely large amount ofair introduced for supporting incomplete combustion through the pipe 12, as compared with the amount introduced through the T 24 and the inlet 9,is` caused to envelop the inner hydrocarbon conewithout becoming intimately and homogeneously mixed therewith. A

While preferably the atmospheric air supplied to the burner forl eecting'the par` tial combustion of the hydrocarbon r`is caused to pass through the preheater wherein'it is heatedtov approximately 1,000 F.,

lll

nevertheless, in the event-it is desired to' f conduct such atmospheric air directly Ato the burner, this canvbe accomplished by adJusting a two-way valve 7 5 so as to short circuit ythe atmospheric air through the by-pass 76,

and then if the cut off valve 77 has been pass into the preheater.' The collection of the finely divided carrb on` particles on 'the collector plates is great- -ly.`,facilitated by the velocity of the stream of carbon-laden gases which impinges against the same, and the same will rapidlector shown in Fig. 7, is maintained atI about 10 and well below the level of the longitudinal axis thereof when emplo ing a collector of a dimension of about 8 long, about 30 wide and havin plates of the dimensions herein specied as thereby back pressure which occurs when the free space for the passage of the gases through the collector is undulyl reduced, can be avoided, provided, of course, the other necessary factors to the successful operation are maintained within the limits herein specified.

Not only is the circulation tank of extremely largev size important where air cooling of the `ink vehicle returned from the collector is resorted to, but by using large .quantities of Vehicle the most intimate mix-ing of the carbon pigment with the ink is possible, so that the necessity for prolonged treatment of the ink in an ink mill is avoided. Furthermore, the direct collection and absor tion of the soot in the ink eliminates e necessity for handling, packing and shipping from a distant point of manufacture to the ink works of the bulky dry soot and the attendant expense.

While air or steam may be used, the steam has a cooling effect on the flame and is detrimental to that extent as it produces a lower yield of soot. Ordinarily, therefore, it is only used for cleaning the burner when the apparatus is shut down.

The herein described soot solids differv from the finest grades of lamp black produced from hydrocarbon oil and from carbon produced from hydrocarbon gas in that it has a tinctorial strength intermediate the two and the lamp black has Ya decidedly bluer tone than my improved soot product, while on the other hand, the carbon black is of a decidedly browner tone than my soot product. Consequently, I have elected to use the term soot to describe m improved product because of the aforesai characteristics thereof.

While the speed of the gases leaving the furnace should notbe below a velocity of 500 per minute and preferably being maintained at about 3,000`per minute,'it is essential for the proper precipitation ofwtheppoilladen soot that the velocity of the soot laden gases in the collectorV should not, in order to prevent the entrainment of the precipitated flakes in the gases through the outlet 72, exceed 500 ft. per minute, being preferably but 250 ft. per minute. This is accom- A32 collector able to have the plates 36 mounted` uite i loose on the square portion of the sha in order that the individual vibration of the plates will periodically dislodge the soot when thel same has accumulated to a reasonably thick layer thereon. Furthermore, in such an event, the dry soot particles are removed at intervals through a man-hole (not shown). The preheating of the air to say 1,000 F. increases very materially the eld of soot per gallon besides improving t e quality of the soot since it requires that a smaller quantity of oil completely consumed in order to obtain the requisite temperature for eifecient operation with the consequence that not only are small quantities of oil and air introduced into the furnace, but a larger percentage of the oil introduced into the furnace decomposed into soot and the soot so obtained because of the smaller quantity ofair .and oil required when preheating is resorted to is exposed to a smaller flame and hence is roasted or graphitized to a lesser extent than were the air not preheated to a temperature between 500 to 2000 F.

While an excellent quality of soot, which is superior to the best grades of lamp black is obtainable when employing but a single without de arting degree combustion, necessary to meet the p requirements of the ink making portions of the aparatus may employed in a furnace of the size herein described without in any way impairing the quality of the soot obtained.

While I prefer the type of pre-heater disclosed, nevertheless under certain conditions of operation, it may be desirable to utilize the heat which can be obtained by burning the waste gases recoveredafter they removal of the soot therefrom for the preheating of air, oxygen or like oxidizing medium prior to its being brought into contact withinthe furnace with the hydrocarbom The expression black pigment consisting of finely divided black carbon is used in the generic sense to include either lamp black,

the product resulting from the decomposi- :dol

lIl() ALetters Patent is I 'claim-and'desire to obtain byIl United States 1. The method'of making black pigment consisting of finely divided carbon particles which comprises decomposingI av hydrocarbon oil into free'carbonandH gases at a tem-v perature substantially of betweenv2,000 .F'. and 3,000 F. yand in an atmosphere wholly incapable of supporting complete combus tion, rapidly removing the resultant carbonladen gases fromthe zone of combustion at Aa substantially constant velocity and not less than 500 it. per minute, then coolingr the gases while in'transit to temperatures substantially between 300 F. and 1,100 F. while still maintaining the speed of jsuch gases in excess of 500 ft; 'per minute and effecting the separation of the carbon particles from the products of combustion carry- -ing the same in suspension.

2. The method of making black pigment yconsisting of finely divided carbon particles.l which comprises decomposing" a hydrocar" bon into free carbon and gases at a tempera-` ture substantially oflbetween 2,000 F,A and 3,000 F. and in an atmosphere wholly incapable of supporting complete combustion, rapidly removingthe resultant carbon-laden vgases from the zone of combustion at a sub.- stantially constant velocity and not less than 500 ft. per minute, then cooling the gases while in transit to temperatures substantially of between 300 F. and 1,100" F. while still maintaining the speed of such gases in excess of 500 ft. er minute, causing said carbon-laden gas to lmpinge against an interposed film of an oil vehicle extendingl at an angle to the direction of flowof such v gases, continuously withdrawing saidve` hicle Afrom contact with said gases and caus' ing the same to directly mix with a considerably larger quantity of another portion of the same vehicle while the mixture is being subjected to a cooling action at a point distantl from the meeting point of said vehicle with said carbon-laden gases and continue ously returning the cooled blended vehicle into contact with further quantities of such cooled carbon laden gases. j

3. -The method' of making black pigment consisting of nely divided 'carbon particles which comprises decomposing! a hydrocarbon into free carbon and gases atl a temperature substantially of between 2,000 F.

and 3,000 F. and in an atmosphere wholly incapable of supporting completey combustion, rapidly removing the'resultant carbonladen gases from the zone of combustion at a substantially constant velocity and not. less than 1,000 ft. per minute nor more vthan 6,000 ft.. per minute, thencooling the gases while in transit' -to temperatures substantially ofbetween 300 F. .and 1,100 F.

while still maintaining the :speed of-such gases in excess of`1,000`ft. per minute, caus- `rg said carbon-laden gas to impinge'against a sheet of an oily ink vehicle extending at# an angle to the"direc.tion` of iow of suchV gases maintained in continuous circulation,

'withdrawing said vehicle -from contact with saidv gas and causing the same to directly.

mixwith ya' considerably larger quantity of another Iportion ofthe same vehicle while the mixture is being subjected to a cooling action ata lpoint d1stant from the meeting point of said vehicle with said carbon-laden gases and continuously returning the cooled blended vehicle in .the `form-of a sheet into contact with further quantities of such cooledcarbon-laden gases. i. f

4. Thelmethod of making/black pigment consisting of finely divided carbon particles which comprises decomposing a. hydrocarbon intoifreecarbonf and Y'gases at a tem-` perature substantially of between 2,000 F. and 3,000 F. and in an atmos here wholly incapable of supporting complete combustion, rapidly removing the resultant carbon# laden gases from the zoneof` combustion at a substantially 'constant velocityv and not less -than v2,000ft. per-minute ynor morethan 6,000 f t. per minute,- gradua lly cooling, without.' suddenlyvchilling, the gases while in transit .to temperatures.,substantially of maintaining the speedof such gases in excess of 12,000 ft. per minute, causing said carbon-laden gas to impinge against an in-l terposed film of` an oil vehicle extending at an angle to the direction of ow. of such gases maintained in continuous circulation,

withdrawing said vehicle from contact withv said gases andv causing it to directly mix with a considerablylarger quantity of another portion of the same vehicle while thej mixture is being subjected tofa cooling ac' tion at a point distantv from the meeting .and substantially of between 2,000 F. and

3,000 F. rapidly -removing the kresultant carbon-laden gases from the zone of combustion at a velocity` of' not less than 1,000 nor more than 6,000 ft. per minute, gradually cooling said gases while vin transit to a temperature below 1,100 F. and' in excess of ,250 F., causing said cooled gases while still moving at-a high velocity and while still Y heated to a temperaturesubstantiall of be- `againstv a body of oildisposed in the form o a moving lm while preventing delelao terious back pressure upon the zone of 'combustion.

6. The'method of making black pigment consisting of finely;1 divided carbon particles I which comprises t e incomplete combustion ofhydrfocarbon into free carbon and gases at a'temperature in excess of 2,000 in an atmos here wholly incapable of supporting com ete combustion, rapidly removing 10 the vres tant carbon-laden gases from the Y zone of combustion at a substantiall 'constant velocity and not less than 500 nor more than 6,000 ft. per minute, cooling said gases vwhile in translt to a temperature substantially of between 250 F. and 1100 F., causin said cooled ases while still moving at big velocity an while still heated substantially of between 250 F. and 1100 F. to impin e against a film of a circulatin gg ink vehic e, continuously removin said in vehicle from contact w1th the caion-laden gases and causing the same to mix with several times its volume of the vehicle in another portion of a closed c cle while aircooling the same and returning vthe cooled vehicle into contact with further quantities of such carbon-laden gases.

7. In an apparatus for making printing ink, the combination comprising a furnace having a metallic, water-jacketed'top for v effecting destructive decomposition of a hydrocarbon without the extensive combustion thereof, a liquid scrubber, air-cooled means interposed between the scrubber and the v furnace adapted to conduct the decomposition roducts from said furnace to said scrub er, a circulatory tank of considerably greater capacity than said scrubber in' communication therewith, means for maintaining the circulation of said gases through the furnace and the scrubber and separate means for effecting the circulation of the oil vehicle through the scrubber and the circulation tank.

8. In an apparatus of the character described, the combination comprising a furnace, a burner compartment at one end thereof, having an oil burner projecting thereinto for efecting the combustion of a hydrocarbon oil, separate means for supplying air and hydrocarbon oil under pressure to the burner, a hollow bale of refractory material extending axially of the burner compartment to envelo and protect the flame as it issued from the urner frbm extensive lateral exposure to air currents, an air conduit adapted to deliver air throu h the wall of the burner compartment an pro'ect the same a ainst the outer longitudma surface ofthe aie, a transverse passage formed intermediate the rear end of the baiile and the front end of the furnace roper arranged to direct air at an an le betweenand 90 66 to the axis of the ame against the same as the combustion of the it issues from said bafllin envelo whereby ydrocar on oil 1s confined principally to the outer portion of the ame and reduced to a minimum in the central portion thereof and the length of the flame in the furnace considerably shortened, means atthe far end o f thevfurnace of considerable extent. and surface for conducting the carbon-laden gases from` the furnace and effecting the gradual cooling by the atmos here of' said carbon-laden gases, a scru ber in communication with said conducting means, a circulation tank of several times the capacity of said scrubber in communication with the latter and means for circulating oil through such scrubber and thence through said circulation tank and thence back to the collector.

9.' lfnv an apparatus for making printing ink, the combination comprising a furnace for eifecting destructive decomposition of ahy drocarbon without the extensive combustion fthereof, a collector, including an electrical smoke precipitator, air-cooled means interposed between the collector and the furnace adapted to conduct the decomposition products from said furnace to said collector, and

tion of a hydrocarbon, said furnace having anoutlet at one end, a scrubber in communication with the said outlet, said scrubber having an inlet in communication with the outlet of said furnace, means for discharging a liquid into intimate contact with the products of combustion delivered into said scrubber and an electrical' precipitator associated with said scrubber and adapted to effect the precipitation of impure soot from the gases passing through said scrubber.

11. rlhe method of making black pigment consisting of nely divided carbon particles which comprises decomposing a hydrocarbon into free carbon: and gases at a temperature substantially of between 2,000 F. and 3,()00 F. and in an atmosphere wholly incapable of supporting complete combustion, rapidly removing the resultant carbon-laden gases from the zone of combustion at a substantially constant velocity and not less than 500 ft. per minute, gradually cooling, without `suddenly chilling, the gases while in transit -to temperatures substantially between 300 F. and 1,100 F. while still maintaining. the speed of such gases in excess of 500 ft. per minute, effecting the separation of the carsov lll

are travelling at a greatlyreduced velocity as compared with the velocity of thegases issuing from the furnace but without causing a deleterious back pressure upon the gases in the furnace.

12. The method of making carboniferousink which consists in .eiecting the incom-4 plete combustion of a hydrocarbon, cooling the products of combustion, effecting the in.

timate mixing of the products of -combus- 1 tion with a iilm of oil while the same are travelling at high speed and .effecting the precipitation of oil-laden soot flakes from the unabsorbed products of combustion by causing the same to pass through an electrical field produced by a non-disruptive corona discharge.

13. The sub-process which consists in effecting the intimate mixture of the hot de composition products resulting from the incomplete combustion of a hydrocarbon with an oily vehicle in the form of a film composed of minutely sub-divided 4oil particles and then subjecting the oil and soot-laden gases not absorbed by such vehicle to the action of an electric field produced by a high tension non-disruptive corona discharge to precipitate sticky oil-laden soot flakes therefrom.

le. The sub-process which consists in effectlng the intimate mixture of the hot decomposition products resulting from the `to mix with an extremely large body of. a

similar vehicle in order to ei'ectively mix and cool the soot and oil mixture and repeatedly returning the cooled mixture into contact with further quantities of soot-laden gases produced by such combustion.

15. The method of making black pigment consisting of finely divided carbon whichcomprises the incomplete decomposition of a hydrocarbon 011 by means of an oxidizing medium preheated to a temperature substantially of between 500 F. and 2000 F. such decomposition being eiected at a temperature in excess of 2000 F., rapidly removing the resultant carbon-laden 4gases frqm the zone of combustion at a substantiallyiconstant velocity and notless than 500 ft. per minute', then cooling the gases while in transit to temperatures substantially of between 300 F. and 1100 F. while still maintaining the speed of such gases in excess of 500 ft. per minute and e'ecting the separation of the carbon particles from the products of combustion carrying the same in suspension.

16. The method of making black pigment consisting of finely divided carbon which comprises the incomplete decomposition of a hydrocarbon oil by means of an oxidizing medium preheated to a temperature substantially of between 800 F. and 1200 F., such decomposition being eEected at a temperature in excess of 2000 F., rapidly removing the resultant carbon-laden gases from the zone of combustion at a substantially constant velocity and not less than 500 ft. per minute, then cooling the gases while in transit to temperatures substantially of between 300 F. and 11.00 F. while still maintaining the speed of such ases in excess of 500 ft. per minute and e ecting the separation of the carbon particles from the products of combustion carrying the same in suspension.

17.' The method which comprises decomposing a hydro-carbon oil into free carbon and gases at a temperature substantially o between 2000 F. and 3000 F. and in an atmosphere wholly incapable of supporting complete combustion, rapidly removing the' resultant carbon-laden gases 'from the 'zone of combustion atV a. substantially constant Velocity and not less than'-'gOO ft. per minute, then cooling the gases while 'in translt to temperatures substantially between 300 F. and 1100" F. while still maintaining the speed of such ases in excess of 500 ft. per minute and e ecting the separation of the carbon particles from.- the products o coinbustion carrying the same 1n suspenslon 1ncluding. the electrical preclpitatlpn of at least 'a portion of such carbon particles from the products of -combustion carrying the same in suspension while such products vofA co'mbusti'on are travelling at a greatly reduced velocity as Acompared, with 4the velocity of the gases issuing from the furnace and without causing deleterious .back pressure from the gases inthe furnace. d

Signed at New York city, in the county of New York and' State of New York, this 26th day of February, 1927.

AMOS'L. MILLER, 

